The high temperature brazing alloys based on Ni, Co or Fe, commonly used in joining or treating gas turbine engine components, have experienced certain undesirable properties when compared with the properties of the alloy of members with which they are associated, such as in joining. These properties include lower room and elevated temperature ductility, a significantly lower remelt temperature and lower mechanical strength properties. The deleterious properties of one form of the alloys to which the present invention relates are the direct result of B or Si, or both, additions necessary to reduce the alloy melting temperature to below that of the alloy of the members being processed.
During evaluation of the method described in U.S. Pat. No. 4,098,450 - Keller et al., issued July 4, 1978 and assigned to the assignee of the present invention, it was recognized that such elements as B and Si form volatile fluoride compounds when exposed to a fluoride ion atmosphere at elevated temperatures. The disclosure of such Keller et al. patent is incorporated herein by reference.